Disposable syringe



Patented Oct. 3, 1950V UNITED `STATES PATENT oFFlcE y DISPOSABLE SYRINGEArthur E. Smith, Los Angeles, Calif. i Application duly 19, 1947, SerialNo. 762,148

3 Claims. (Cl. 12S- 220) This invention relates to disposable syringes.

rihe general object of the invention is to pro vide an improveddisposable syringe useful for the injection of medicinal preparationsand wherein a novel plunger member is employed-for causing theinjection.

.A further object of the invention is to provide a novel plunger for usein a syringe.,

Other objects and advantages of the invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings, wherein:

Fig. l is a side elevation of a my invention;

Fig. 2 is a central, sectional view on a large scale of a syringe;

Fig. 3 is a view similar to Fig. 2 showing a modication, and

Fig. 4 is a view similar to Fig. further modication.

Referring to the drawing by reference characters, I have shown myinvention as embodied in a syringe indicated generally at ID. As shownthe syringe includes an ampule or barrel Il, which may be made ofplastic and which is cylindrical and has a stopper l2 which may be madeof rubber and which is mounted in one end of the ampule. The stopperincludes a projecting flange I3 and has an inwardly directed recess Illand an outwardly directed recess I5 with a diaphragm I6 between therecesses.

The syringe includes a plunger, indicated generally at Il. The plungeris shown as tubular and may be made of plastic or glass. A cylindricalpiston stopper I 8 is arranged within the plunger and has a projectingend I 9 which has piston rin-g forming beads 2i! integral therewith. Ishow three of the beads 2U although the number may be varied as desired.

The piston stopper I8 has a bore 2i therethrough. At its inner end thebore 2! is enlarged to form a recess 22 and in this recess I arrange aprotuberance 23 on a hypodermic needle 24 which extends forwardlythrough the bore ZI and has its forward end arranged in a bore 3U in afront member 3l. The front member includes a liange 32 which may begrasped by the lingers of the operator during an injection. The frontmember includes a recess 33 which communicates with the bore 3B. Theneedle extends forwardly from the front member and at its free end issharpened as at 34. The forward end of the front member tapers as at 35and is engaged by a cap 36 which surrounds the needle and maintains thelatter in sterile condition.

syringe showing 2 showing a In use the parts are constructed asdescribed and are assembled preferably with the plunger El fullyadvanced into the ampule. A hypodermic needle is then inserted throughthe diaphragm i6 and the medicament or solution` to be injected isforced into the ampule and as this occurs the piston stopper I8andplunger I'I are caused to be moved awayfrom the stopper I2. Theamount of movement of the piston indicates the amount of medicine withinthe ampule and when the correct amount has been passed into the ampulethe hypodermic needle is withdrawn from the diaphragm It. The hole isself-sealing due to the resiliency of the material. The cap 35 is thenplaced `on the tip 35 to maintain the needle 34 in sterile condition.

In use the cap 35 is withdrawn and the needle Sli is inserted in thepatient. The barrel II is then pushed forward a slight distance and thenwithdrawn and if blood appears in the ampule, it will show the needle isin a blood vessel, whereupon the needle may be withdrawn and correctlyinserted. When upon withdrawal of the barrel l I there is no appearanceof blood within the barrel, this fact will indicate to the operator thatthe needle has been correctly inserted. The ampule is then pushed alongthe plunger, thus reducing the volume within the ampule and causing themedicamentous substance to be forced through the needle 24. The needleis held securely in place due to the fact that it is resiliently engagedby the wall of the plunger bore. The protuberance 22 on the needle alsoprevents forward movement of the needle.

In the modication shown in Fig. 3 the construction is similar andincludes a syringe IU which employs an ampule I I', and a stopper I2',having a flange I 3 thereon. The plunger includes a body lill havingintegral piston ringforming beads 4I thereon. The plunger includes anaxial recess l2 which communicates with a bore #i3 in which a needle itis arranged. The needle lill has a protuberance i5 arranged in therecess 42. The plunger includes a front member 46 having a flange 4l andhaving a tip 48.

In the modication shown in Fig. 4 the syringe I0 includes an ampule II"having an integral closure I2 which has an integral llange I3. Theplunger includes a body 4G which has resilient piston rings lll arrangedin grooves 44". The plunger includes an axial recess 42' whichcommunicates with a bore 43. The bore 43 communicates with a needle 4darranged in the forward part of the bore 43. The needle is surrounded byla protuberance 45. The plunger -Jl includes a front member portion 46'which has a ange 41 thereon and a tapered tip 48'.

The modified types of syringe are used in the same manner as thatdescribed in connection with Figs. 1 and 2.

From the foregoing description it Will be apparent that I have inventeda novel hypodermic syringe which may be economically manufactured andwhich is highly efficient for its intended use.

Having thus described my invention, I claim:

1. A syringe comprising a cylindrical ampule member and a plunger havinga piston forming portion thereon forming a closure for and slidable inone end of the ampule, a closure for the other end of the ampule, anelongated body having an axial bore therethrough, the inner end of saidbore being enlarged, a hypodermic needle extending through said plungerbore and being xedly held in place by its resilient engagement With theWall of the plunger bore, said needle having a protuberance thereondisposed in the enlarged portion of the plunger bore, said plungerhaving a fingerr engaging portion thereon.

2. yA syringe comprising a cylindrical ampule member and a plungerhaving a piston forming portion thereon forming a closure for andslidable in one end of the ampule, a closure for the other endrof theampule, said plunger including an elongated body having an axial boretherethrough, the inner end of said bore opening into the ampule, ahypodermic needle extending through said plunger bore, said plunger boreincluding an enlarged portion, said needle having a protuberance thereondisposed in the enlarged portion of the plunger bore, said plungerincluding a projecting tip having a finger engaging flange, said needlebeing xedly held in place by its resilient engagement with the Wall ofthe plunger bore.

3. A syringe comprising a cylindrical ampule, a plunger, a stopperdisposed in one end of the ampule, said plunger including a hollow,tubular body having a piston stopper therein at one end, said pistonstopper including a portion projecting beyond the inner end of the bodyand engaging the inner wall of the ampule, and forming a closure for theother end of the ampule, said piston stopper having an axial boretherethrough, the inner end of said bore being enlarged, and ahypodermic needle extending through said piston bore, said plungerhaving a front member thereon, said front member including a portionWithin the plunger and a projecting tip, said front member having afinger engaging flange, said front member having an axial bore, saidneedle extending through said front member bore, said needle being'lxedly secured in the front member and piston stopper bores by itsresilient engagement with the Wall of the bores.

ARTHUR E. SMITH.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number l Name Date 1,712,070 Cressler May 7, 19291,715,771 MacGregor June 4, 1929 1,817,003 Hein Aug. 4, 1931 1,848,711Hall Mar. 8, 1932 FOREIGN PATENTS Number Country Date 17,069 GreatBritain July 22, 1909

